Mya Arenaria Class: Bivalvia, Heterodonta, Euheterodonta

Home , Heterodonta, Mya (bivalve), Myida, Myidae, Nautilus (genus)

Mya arenaria Class: Bivalvia, Heterodonta, Euheterodonta

Order: Imparidentia, Myida Soft-shelled clam Family: Myoidea, Myidae

Taxonomy: Mya arenaria is this species Body: Body is egg-shaped in outline (Fig. 1; original name and is almost exclusively used Ricketts and Calvin 1952) (see Fig. 305, Ko- currently. However, the taxonomic history of zloff 1993). this species includes many synonyms, over- Color: lapping descriptions, and/or subspecies (e.g. Interior: A crystalline style (consisting Mya hemphilli, Mya arenomya arenaria, of a gelatinous cortex and liquid core, Lawry Winckworth 1930; Bernard 1979). The sub- 1987) resides in a sac lined with cilia. The genera of Mya (Mya mya, Mya arenomya) cilia allow the style to rotate and press against were based on the presence or absence of a a gastric shield within the stomach, aiding in subumbonal groove on the left valve and the digestion (Lawry 1987). In M. arenaria, the morphology of the pallial sinus and pallial crystalline style can be regenerated after 74 line (see Bernard 1979). days (Haderlie and Abbott 1980) and may contribute to the clam’s ability to live without Description oxygen for extended periods of time (Ricketts Size: Individuals range in size from 2–150 and Calvin 1952). The ligament is white, mm (Jacobson et al. 1975; Haderlie and Ab- strong, and entirely internal (Kozloff 1993). bott 1980; Kozloff 1993; Maximovich and Two types of gland cells (bacillary and goblet) Guerassimova 2003) and are, on average, comprise the pedal aperture gland or glandu- 50–100 mm (Fig. 1). Mean weight and lar cushion located within the pedal gape. It is length were 74 grams and 8 cm situated adjacent to each of the two mantle (respectively) in Wexford, Ireland (Cross et margins and aids in the formation of al. 2012). Individual weight varies seasonal- pseudofeces from burrow sediments; the ly and is greatest just before spawning and structure of these glands may be of phyloge- the smallest just after (range, 100–200 mg netic relevance (Norenburg and Ferraris ash-free dry weight, Wadden Sea, Zwarts 1992). 1991). Exterior: Color: White with gray or dark, yellowish Byssus: brown periostracum on shell edges, creating Gills: a rough outermost layer. Siphons are dark Shell: Shell is soft, thin, fragile (hence “soft (Haderlie and Abbott 1980; Kozloff 1993; shell clam”, Kozloff 1993; Coan and Valentich see Fig. 3, Zhang et al. 2012). -Scott 2007), and composed completely of General Morphology: Bivalve mollusks are aragonite (MacDonald and Thomas 1980). bilaterally symmetrical with two lateral The valves have an oval and rounded anterior valves or shells that are hinged dorsally and and a pointed posterior (Kozloff 1993) and surround a mantle, head, foot and viscera gape at each end (Haderlie and Abbott 1980). (see Plate 393B, Coan and Valentich-Scott External shell sculpture is with concentric 2007). Myoid bivalves are burrowers and rings (Fig. 1). borers, with long siphons and hinges with Interior: Deep pallial sinus and spoon- few teeth (Coan and Valentich-Scott 2007).

A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: https://oimb.uoregon.edu/oregon-estuarine-invertebrates and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected]

Hiebert, T.C. 2015. Mya arenaria. In: Oregon Estuarine Invertebrates: Rudys' Illustrated Guide to Common Species, 3rd ed. T.C. Hiebert, B.A. Butler and A.L. Shanks (eds.). University of Oregon Libraries and Oregon Institute of Marine Biology, Charleston, OR.

shaped chondrophore, or triangular projec- stone (Sphenia) or those utilizing the burrows tion, is present on the left valve only of other species (Cryptomya, Paramya) (Haderlie and Abbott 1980; Kozloff 1993). (Zhang et al. 2012). Characters of the Myidae Left and right adductor muscle scars are the include a shell that is not cemented to the same size but very different in shape (Fig. substratum, valves that are (relatively) mor- 2). phologically similar, a dorsal margin without Exterior: Left and right valves are of ears, a hinge with an internal ligament in a similar morphology, which is long and egg- distinct resilifer or chondrophore that is spoon shaped, with shells convex, thin and brittle shaped and present on the left valve (Coan (Fig. 4). Low concentric growth striae on and Valentich-Scott 2007). Cryptomya anterior and posterior ends are different: species are characterized by hinge without anterior are more blunt and posterior are tooth-like process anteriorly on the right valve. pointed, but both ends gaping (Packard Mya, on the other hand, have thin shells, ga- 1918). Beaks small, bent posteriorly, and ping anteriorly and posteriorly and commargi- slightly anterior of center (Fig. 2). nal growth lines (Zhang et al. 2012). Hinge: Valve areas dissimilar and There are only three local myid species with spoon-shaped chondrophore in left including Platyodon cancellatus, Mya arenaria valve. Right valve is with tooth in opposition and Cryptomya californica (“the false Mya” to chondrophore (Fig. 3). No hinge plate see description in this guide). Platydon can- teeth (cardinal or lateral). cellatus can be distinguished from the latter Eyes: two species because its shells are heavy and Foot: with wavy commarginal sculpture and a round Siphons: Long, large siphons are fused, anterior. It has a truncate, gaping posterior non-retractable (Coan and Valentich-Scott end covered with periostracum. It also bores 2007; Tan and Beal 2015), and dark in color into rock and hard clay while M. arenaria and (Haderlie and Abbott 1980). C. californica burrow into sand or mud. The Burrow: Unlike the other local member of shells of the two latter species are relatively the Myidae, Cryptomya californica (see de- thin. In M. arenaria, the pallial sinus is deep scription in this guide), M. arenaria has long and individuals reach sizes of 150 mm, while siphons and can be found in relatively deep in C. californica the pallial sinus is shallow, burrows up to 40 cm (Haderlie and Abbott inconspicuous and individuals tend to be 1980; Kozloff 1993; Coan and Valentich- smaller (30 mm) (Coan and Valentich-Scott Scott 2007; González et al. 2015). 2007). Mya arenaria is found as deep as 40 cm and is not necessarily near Callianassa Possible Misidentifications californiensis burrows, where one might find There are five bivalve subclasses Cryptomya californica. The siphons are M. based on morphology and fossil evidence arenaria are also longer than those of C. cali- and one of those is the diverse Heterodonta. fornica (see C. californica, Figs. 1, 6 in this Recent molecular evidence (18S and 28S guide). Additionally, Sphenia luticola is a myid rRNA) suggests that the heterodont order species that may occur in our area, but is Myoida is non monophyletic (Taylor et al. found offshore in rocks and within kelp hold- 2007). The family Myidae includes 25–40 fasts (Coan and Valentich-Scott 2007). Juve- species worldwide, which can be divided in- nile Mya are not easily distinguished from to groups such as those that are burrowing Sphenia species, but Mya can be recognized (Mya), those that are attached to shells or by a large continuous pallial sinus (Coan

1999). and Abbott 1980; Ricketts and Calvin 1952). Mya arenaria may be confused with Common on the Atlantic Coast and Europe in other local common clams, e.g. Saxidomus, areas of low salinity (e.g. Baltic Sea, Kozloff Tresus, Tellina or Macoma species. These 1993). It has crowded out the native Macoma genera do not have an internal ligament or a spp. on the Pacific coast in some areas (Keep chondrophore. Small Tresus can otherwise and Longstreth 1935). In the Cold Temperate be mistaken for M. arenaria. Small Tellinid Northwest Atlantic biogeographic province, six clams have an external ligament without a genetic clusters of M. arenaria were observed nymph, and lateral hinge teeth, which M. spanning seven distinct ecoregions. Those to arenaria lack. Macoma species (see de- the north were defined by geographic barriers scriptions in this guide) are very like Tellina, and selection processes and those to the but their shells are always a bit flexed, they south were likely the result of and increased have no lateral teeth, and no internal colora- with geographic distance only (St-Onge et al. tion. Furthermore, where M. arenaria is 2013). abundant is in upper reaches of estuaries Local Distribution: Local distribution in Coos where salinity is reduced, species in the and Yaquina Bay as well as the Suislaw, genera Saxidomus and Tresus are not usua- Umpqua, Tillamook, Alsea and Columbia es- lly found. tuaries. Habitat: Mud and sand of bays with sand, Ecological Information mud, gravel mix (Kozloff 1993; Coan and Range: Type locality is Europe (Zhang et al. Valentich-Scott 2007), often in upper reaches 2012). Current eastern Pacific distribution where salinity is reduced, but requires com- from Alaska to San Diego, California plete protection, as it cannot burrow or main- (Haderlie and Abbott 1980). Current popula- tain itself in a shifting substratum (Ricketts tions introduced from the Atlantic coast with and Calvin 1971). Very tolerant of extreme oyster spat in 1874 in San Francisco (Coan conditions (e.g., anaerobic or foul mud, brack- and Valentich-Scott 2007), although it ish water, temperatures below freezing, Rick- appears in the fossil record (Ricketts and etts and Calvin 1971; Haderlie and Abbott Calvin 1971) in California and Vancouver 1980). Can live without oxygen for eight days (Packard 1918). However, M. arenaria is (Ricketts and Calvin 1952) and it is thought not represented in local Native American that the shell serves as an alkaline reserve to mounds (Kozloff 1993). The neutralize lactic acid from anaerobic respira- palaeontological history of M. arenaria was tion (Haderlie and Abbott 1980). In a study described by Fujie (1957, 1962), as the spe- testing the effects ocean acidification on M. cies originated in the Pacific in the Miocene, arenaria, sedimentary aragonite saturation spread to the Atlantic into the Pliocene, be- resulted in a negative relationship with disper- came extinct in the Pacific northwest by the sal and a positive relationship with clam bur- Pleistocene was re-established and intro- rowing depth (Clements and Hunt 2014). duced from Atlantic populations in 1880s Conversely, increases in proton concentration and was re-introduced to the eastern Atlan- yielded a negative relationship with burrowing tic and Pacific during the Pleistocene depth (Clements and Hunt 2014). Thermal (Rasmussen and Heard 1995; Zhang et al. stress (e.g., associated with climate change) 2012). Following introduction, M. arenaria is accompanied by oxidative stress in marine spread northward to Willapa Bay, Washing- mollusks, including M. arenaria, and leads to ton in 1880 and Alaska in 1950s (Haderlie the mitochondrial production of reactive oxy-

gen species (Abele et al. 2002). Mya are- common estuarine species is often used in naria individuals respond to hypoxia by re- toxicity and biomarker tests, where effects of ducing burrow depth and increasing siphon tributyltin (TBT) included masculinizing of fe- extension (Taylor and Eggleston 2000). males, sex ratios skewed toward male, and Salinity: Tolerates brackish water and re- delayed male maturation (Gagné et al. 2003). duced salinity, as well as full salt water Life-History Information (Haderlie and Abbott 1980; Kozloff 1993). Reproduction: Dioecious with, at most, two Temperature: Range limited to cool areas, periods of sexual maturation and spawning, although this species can also tolerate tem- one in the fall (primary maturation period) and peratures below freezing (Ricketts and Cal- one in spring (secondary maturation) vin 1952). Eastern Atlantic southern distri- (Chesapeake Bay and St. Lawrence estuary, bution set by critical maximum temperature Roseberry et al. 1992). A continuous repro- of 28˚C (Rasmussen and Heard 1995). ductive period from April to October occurs in Tidal Level: Found from 15–40 cm depths New England (Pfitzenmeyer and Shuster in mud habitats (Packard 1918) and 1960). Atlantic species tend to spawn from intertidal to 20 m (Zhang et al. 2012). June to August and eggs 60–80 µm diameter Associates: Commensal pea crabs, Fabia (Haderlie and Abbott 1980). In Cape Cod, subquadrata, F. concharum, Pinnixa faba, P. gametogenesis began during late winter and littoralis (Ricketts and Calvin 1971; Haderlie spawning was complete by the end of and Abbott 1980). Co-occurs with Macoma summer (September, Ropes and Stickney balthica and the lugworm, Arenicola marina, 1965). Populations in Wexford, Ireland had in the Wadden Sea (Günther 1992; Strasser sex ratios of 1:1.15 (female to male) and were et al. 1999). The abundance of A. marina, a ripe and spawning in August, completed in bioturbator, has a negative effect on recruit- November (Cross et al. 2012). ment in M arenaria (Strasser et al. 1999). Life-history characteristics appeared to Domoic acid (a neurotoxin), released from correlate along a latitudinal gradient in the and ingested with the diatom Pseudo- northeast coast of the United States: individu- nitzschia, is biodegraded in M. arenaria with als in southern populations grew faster, exhib- the help of autochthonous bacteria (Stewart ited greater variation in juvenile mortality, had et al. 1998). larger egg sizes (range 25–45 µm), lower egg Abundance: Mya arenaria can be very density (range 495–1,541), decreased longev- abundant and often occurs with a patchy ity (4–15 years), and larger size at maturation distribution (e.g., 177 individuals/m2, St. (see Table 1, Appeldoorn 1995). In San Lawrence estuary, Roseberry et al. 1992). Francisco, CA, gametogenesis began in late Locally abundant in Yaquina, Siuslaw, and February and spawning occurred from April to Umpqua estuaries, and in some parts of October (Rosenblum and Niesen 1985). Coos Bay where it is “fairly com- Sperm morphology and spermatogenesis of mon” (Haderlie and Abbott 1980). Mya are- the subspecies Mya arenaria oonogai was de- naria was reported as ubiquitous in north- scribed by Kim et al. in 2011. In this species, east and northwest Atlantic (Tan and Beal the spermatozoon was approximately 50 µm 2015). In the Wadden Sea, 50 individuals/ in length. Disseminated neoplasia, a leuke- m2were observed (Strasser et al. 1999; Gün- mia-like disease, occurs in the gonadal tis- ther 1992), and up to 1,000 individuals/ sues of M. arenaria (Barber 1996; Boettger m2reported in Kandalaksha Bay, White Sea and Barletta 2015). The frequency of neo- (Maximovich and Guerassimova 2003). This

plasia increases in spring in Maine (Boettger Brunswick, when individuals are greater than and Barletta 2015). In 1994 in Whiting Bay, 500 µm (Morse and Hunt 2013). Settlement Maine, progressive and potentially lethal may depend on sediment properties (e.g., gonadal neoplasms were observed in 19% grain size, presence of sea grasses, Strasser of individuals, involving up to 100% of gon- et al. 1999). Juveniles and smaller individuals adal follicles. Females were more likely to (< 2 mm) can also be transported hydrody- have neoplasms than males and produced namically (Hunt and Mullineaux 2002). Maxi- fewer, smaller gametes leading to an overall mum transport rates coincided (positive corre- negative impact on reproductive output lation) with peaks in bedload transport: in (Barber 1996). sheltered sandflats, maximum transport rate Larva: Bivalve development generally pro- was 790 individuals/m/day and in exposed ceeds from external fertilization via broad- habitats, maximum transport rate increased to cast spawning through a ciliated trocho- 2,600 individuals/m/day (Emerson and Grant phore stage to a veliger larva. Bivalve veli- 1991). Recruitment is highly variable and gers are characterized by a ciliated velum based on (among others) predation, tempera- that is used for swimming, feeding and respi- ture, and adult-larval interactions. Some re- ration. The veliger larva is also found in search shows that larvae avoid settlement in many gastropod larvae, but the larvae in the areas with high conspecific density two groups can be recognized by shell mor- (Maximovich and Guerassimova 2003, but phology (i.e. snail-like versus clam-like). In see Brousseau and Bagilvo 1988; Günter bivalves, the initial shelled-larva is called a D 1992). -stage or straight-hinge veliger due to the Juvenile: Juveniles are typically less than 2– “D” shaped shell. This initial shell is called a 15 mm in length (Strasser et al. 1999; Tan prodissoconch I and is followed by a prodis- and Beal 2015) and size is generally fixed by soconch II, or shell that is subsequently add- epibenthic predators. Sexual maturity occurs ed to the initial shell zone. Finally, shell se- when individuals are 25–35 mm in length creted following metamorphosis is simply (Brousseau 1979; Rosenblum and Niesen referred to as the dissoconch (see Fig. 2, 1985). Following settlement, significant Brink 2001). Once the larva develops a foot, changes occur in population distributions with- usually just before metamorphosis and loss in the first month, due to post-settlement dis- of the velum, it is called a pediveliger (see persal and predation (Morse and Hunt 2013). Fig. 1, Kabat and O’Foighil 1987; Brink Newly settled individuals and juveniles are 2001). (For generalized life cycle see Fig. 1, prey to a variety of epipenthic predators and Brink 2001.). Young M. arenaria larvae (150 their size and abundance is ultimately con- µm) have a broadly rounded umbo with a trolled by predation (Hunt and Mullineaux short, sloping posterior (see Fig. 4, Brink 2002). Mortality by predation significantly de- 2001). The umbo becomes angled in ad- creases with growth. For example, green vanced individuals and the shoulders be- crabs (Carcinus maenas) reduced 80% of come straight and steeply sloping. Eventu- small (<17 mm) M. arenaria in caged experi- ally, the anterior and posterior ends elongate ments containing 1–5 crabs in Pompuet Har- and are pointed and metamorphosis occurs bour, Nova Scotia (Floyd and Williams 2004). when larvae are 170–230 µm (Chanley and Young M. arenaria (< 30 mm) were most sus- Andrews 1971; Brink 2001). Settlement in ceptible to predation by the snail, Lanutia the Wadden Sea occurs from May to June heros, as 3.5% died/year in the first five years (Günther 1992) and in Mill Cove, New (Maine, Commito 1982). Ultimately, size se-

lective feeding leads to overestimated aver- and Beal 2015), M. arenaria takes up oxygen, age size measurements among juveniles food, algae, and detritus containing iron (Fe) and fast juvenile growth allows for a size ref- and other trace metals (González et al. 2015) uge from epibenthic predators (Wadden by filtering seawater. Compared to other filter Sea, Günther 1992). Additionally, juveniles feeders, M. arenaria may have a low filtration escape predation with severe winters that rate (Jorgensen 1966 in Vincent et al. 1988). result in mortality of predators (Günther Individuals can adapt to varying algal 1992). Mortality significantly decreased 94 concentrations; a low concentration leads to a days after settlement (Günther 1992). reduced siphon opening and valve gape, Longevity: Up to 28 years (Appeldoorn which can occur after several hours of 1995). A 17 years maximum was reported reduced concentrations, while an increase in in Kandalasksha Bay, White Sea algal concentration leads to siphon opening (Maximovich and Guerassimova 2003). within 5–20 min (Riisgard et al. 2003). Over 25 years of monitoring in the White Predators: Shorebirds (e.g., sea gulls), sea Sea, populations of M. arenaria showed al- otters eat exposed adults and larvae are ternatively high and low levels of mortality preyed upon by planktonic predators and (Table 2, Gerasimova et al. 2015). The au- suspension feeders. Adults are prey to thors attributed this variation in mortality to infaunal predators (e.g., gastropods, the unstable habitat early in life and intra- nemerteans) and juveniles live so close to the specific relationships and competition asso- sediment surface that their siphons are often ciated with dense aggregations (Gerasimova nipped off by crustaceans and fish (Tan and et al. 2015). Beal 2015). Additional predators include fish, Growth Rate: Clams as small as 25 mm shrimp, sandworms, crabs (e.g., the green have been found to have mature gametes crab, Carcinus maenas, Wong 2013; Morse (Pfitzenmeyer and Shuster 1965). Individu- and Hunt 2013; Tan and Beal 2015, the blue als approximately 15 mm in length grew 110 crab (C. sapidus, Taylor and Eggleston 2000), µm per day (Günther 1992). Most shell dep- snails (Cross et al. 2012), the stingray, osition occurred from March to November in Dasyatis sabina (Rasmussen and Heard Gloucester, MA (Brousseau 1979). Alt- 1995), and Nereis virens (Morse and Hunt hough external growth rings can be conspic- 2013). Predation by Polinices duplicatus, uous, they may not be an accurate indicator increased with temperature, with individuals of clam age and are not always clearly de- ingesting as many as 96 Mya arenaria/snail/ fined. Instead, internal growth lines, which year (Edwards and Huebner 1977). Carcinus can be seen in thin sections when shells are maenas (green crab) populations decrease sliced from the umbo to the ventral margin, populations of M. arenaria and survival of reliably indicate growth in late spring months clams was seven times greater when preda- before spawning (Prince Edward Island, tion by green crabs was experimentally re- MacDonald and Thomas 1980). The neo- moved (Maine, Tan and Beal 2015). Also a plastic disease, disseminated neoplasia, commercially important species. In eastern which is characterized by excessive and ab- Canada (e.g., Nova Scotia, New Brunswick) normal cell growth is found in M. arenaria the fishery landed 4,500 tons in 1986 and and appears to be transmitted among popu- 3,000 tons in 1988 (Aramaratunga and Misra lations by horizontal transmission (Carballal 1989). Predators of newly settled larvae also et al. 2015). include adults of the same species. There is Food: A suspension and filter feeder (Tan a negative relationship between adult density

and newly settled larvae in both Cerastoder- 7. BOETTGER, S. A., and A. T. BARLETTA. ma edule (40% mortality) and M. arenaria 2015. Effect of reproductive effort on neo- (20% mortality) (André and Rosenberg plasia development in the soft-shell clam, 1991). Mya arenaria. Integrative and Comparative Behavior: In the presence of predators, in- Biology. 55:E17-E17. dividuals increase their burial depth and re- 8. BRINK, L. A. 2001. Mollusca: Bivalvia, p. duce growth (Tan and Beal 2015). Pre- 129-149. In: Identification guide to larval ferred orientation is perpendicular to the marine invertebrates of the Pacific North- principle component of current direction. west. A. Shanks (ed.). Oregon State Uni- This allows siphons to be in line with the cur- versity Press, Corvallis, OR. rent and, presumably, avoids inhalant exhal- 9. BROUSSEAU, D. J. 1979. Analysis of ant contamination (Vincent et al. 1988). growth rate in Mya arenaria using the Von Bertalanffy equation. Marine Biology. Bibliography 51:221-227. 1. ABELE, D., K. HEISE, H. O. PORTNER, 10. BROUSSEAU, D. J., and J. A. BAGLIVO. and S. PUNTARULO. 2002. Tempera- 1988. Life tables for two field populations ture-dependence of mitochondrial func- of soft-shell clam, Mya arenaria, tion and production of reactive oxygen (Mollusca: Pelecypoda) from Long Island species in the intertidal mud clam Mya Sound. Fishery Bulletin. 86:567-579. arenaria. Journal of Experimental Biolo- 11. CARBALLAL, M. L., B. J. BARBER, D. IG- gy. 205:1831-1841. LESIAS, and A. VILLALBA. 2015. Neo- 2. AMARATUNGA, T., and R. K. MISRA. plastic diseases of marine bivalves. Jour- 1989. Identification of soft-shell clam nal of Invertebrate Pathology. 131:83-106. (Mya arenaria Linnaeus, 1758) stocks in 12. CHANLEY, P. E., and J. D. ANDREWS. eastern Canada based on multivariate 1971. Aids for identification of bivalve lar- morphometric analysis. Journal of Shell- vae of Virginia. Malacologia. 11:45-119. fish Research. 8:391-398. 13. CLEMENTS, J. C., and H. L. HUNT. 2014. 3. ANDRE, C., and R. ROSENBERG. 1991. Influence of sediment acidification and wa- Adult-larval interactions in the suspen- ter flow on sediment acceptance and dis- sion-feeding bivalves Cerastoderma persal of juvenile soft-shell clams (Mya edule and Mya arenaria. Marine Ecology arenaria L.). Journal of Experimental Ma- Progress Series. 71:227-234. rine Biology and Ecology. 453:62-69. 4. APPELDOORN, R. S. 1995. Covariation 14. COAN, E. V. 1999. The eastern Pacific in life-history parameters of soft-shell species of Sphenia (Bivalvia: Myidae). clams (Mya arenaria) along a latitudinal Nautilus. 113:103-120. gradient. ICES Marine Science Sympo- 15. COAN, E. V., and P. VALENTICH-SCOTT. sia. 199:19-25. 2007. Bivalvia, p. 807-859. In: The Light 5. BARBER, B. J. 1996. Effects of gonadal and Smith manual: intertidal invertebrates neoplasms on oogenesis in softshell from central California to Oregon. J. T. clams, Mya arenaria. Journal of Inverte- Carlton (ed.). University of California brate Pathology. 67:161-168. Press, Berkeley, CA. 6. BERNARD, F. R. 1979. Identification of 16. COMMITO, J. A. 1982. Effects of Lunatia living Mya (Bivalvia: Myoida). Venus: the heros predation on the population dynam- Japanese Journal of Malacology. 38:185- ics of Mya arenaria and Macoma balthica 204. in Maine, USA. Marine Biology. 69:187-

193. MOVICH, and N. A. FILIPPOVA. 2015. 17. CROSS, M. E., S. LYNCH, A. WHITA- Cohort life tables for a population of the KER, R. M. O' RIORDAN, and S. C. soft-shell clam, Mya arenaria L., in the CULLOTY. 2012. The reproductive biolo- White Sea. Helgoland Marine Research. gy of the softshell clam, Mya arenaria, in 69:147-158. Ireland, and the possible impacts of cli- 25. GONZALEZ, P. M., D. ABELE, and S. mate variability. Journal of Marine Biolo- PUNTARULO. 2015. Oxidative status of gy. 2012:1-9. respiratory tissues of the bivalve Mya are- 18. EDWARDS, D. C., and J. D. HUEBNER. naria after exposure to excess dissolved 1977. Feeding and growth rates of iron. Marine and Freshwater Behaviour Polinices duplicatus preying on Mya are- and Physiology. 48:103-116. naria at Barnstable Harbor, Massachu- 26. GUNTHER, C. P. 1992. Settlement and setts. Ecology. 58:1218-1236. recruitment of Mya arenaria (L.) in the 19. EMERSON, C. W., and J. GRANT. 1991. Wadden Sea. Journal of Experimental Ma- The control of soft-shell clam (Mya are- rine Biology and Ecology. 159:203-215. naria) recruitment on intertidal sandflats 27. HADERLIE, E. C., and D. P. ABBOTT. by bedload sediment transport. Limnolo- 1980. Bivalvia: the clams and allies, p. 355 gy and Oceanography. 36:1288-1300. -410. In: Intertidal invertebrates of Califor- 20. FLOYD, T., and J. WILLIAMS. 2004. Im- nia. R. H. Morris, D. P. Abbott, and E. C. pact of green crab (Carcinus maenas L.) Haderlie (eds.). Stanford University Press, predation on a population of soft-shell California. clams (Mya arenaria L.) in the Southern 28. HUNT, H. L., and L. S. MULLINEAUX. Gulf of St. Lawrence. Journal of Shellfish 2002. The roles of predation and Research. 23:457-462. postlarval transport in recruitment of the 21. FUJIE, T. 1957. On the myarian pelecy- soft shell clam (Mya arenaria). Limnology pods of Japan. Part I: Summary of the and Oceanography. 47:151-164. study of the genus Mya from Hokkaido. 29. JACOBSON, R. W., P. HEIKKILA, and K. Journal of the Faculty of Science Hokkai- S. HILDERBRAND. 1975. Oregon's capti- do University Geology. 9:381-413. vating clams. Oregon State University Ex- 22. —. 1962. On the myarian pelecypods of tension Service, Sea Grant Marine Adviso- Japan. Part II: Geological and geograph- ry Program, and Oregon Dept. of Fish and ical distribution of fossil and recent spe- Wildlife, Corvallis, Or. cies, genus Mya. Journal of the Faculty 30. KABAT, A. R., and D. O'FOIGHIL. 1987. of Science Hokkaido University Geology. Phylum Mollusca, Class Bivalvia, p. 309- 11:399-430. 353. In: Reproduction and development of 23. GAGNE, F., C. BLAISE, J. PELLERIN, marine invertebrates of the northern Pacif- E. PELLETIER, M. DOUVILLE, S. ic Coast. M. F. Strathmann (ed.). Universi- GAUTHIER-CLERC, and L. VIGLINO. ty of Washington Press, Seattle, WA. 2003. Sex alteration in soft-shell clams 31. KEEP, J., and J. LONGSTRETH. 1935. (Mya arenaria) in an intertidal zone of the West coast shells: a description in familiar Saint Lawrence River (Quebec, Canada). terms of the principal marine, fresh-water, Comparative Biochemistry and Physiolo- and land mollusks of the United States, gy: C-Toxicology & Pharmacology. British Columbia, and Alaska, found west 134:189-198. of the Sierra. Stanford University Press, 24. GERASIMOVA, A. V., N. V. MAXI- Stanford, CA.

32. KIM, J., J. CHUNG, and Y. PARK. 2011. 41. RASMUSSEN, E., and R. W. HEARD. Ultrastructures of germ cells during sper- 1995. Observations on extant populations matogenesis and taxonomic values in of the softshell clam, Mya arenaria Linne, sperm morphology in male Mya arenaria 1758 (Bivalvia: Myidae), from Georgia oonogai (Heterodonta: Myidae). Korean (USA) estuarine habitats. Gulf Research Journal of Malacology. 27:377-386. Reports. 9:85-96. 33. KOZLOFF, E. N. 1993. Seashore life of 42. RICKETTS, E. F., and J. CALVIN. 1952. the northern Pacific coast: an illustrated Between Pacific tides : an account of the guide to northern California, Oregon, habits and habitats of some five hundred Washington, and British Columbia. Uni- of the common, conspicuous seashore in- versity of Washington Press, Seattle. vertebrates of the Pacific Coast between 34. LAWRY, E. V. 1987. Cryptomya californi- Sitka, Alaska, and Northern Mexico. Stan- ca (Conrad, 1837): observations on its ford : Stanford University Press, Stanford. habitat, behavior, anatomy, and physiolo- 43. —. 1971. Between Pacific tides. Stanford gy. Veliger. 30:46-54. University Press, Stanford, California. 35. MACDONALD, B. A., and M. L. H. 44. RIISGARD, H. U., C. KITTNER, and D. F. THOMAS. 1980. Age determination of SEERUP. 2003. Regulation of opening the soft-shell clam Mya arenaria using state and filtration rate in filter-feeding bi- shell internal growth lines. Marine Biolo- valves (Cardium edule, Mytilus edulis, Mya gy. 58:105-109. arenaria) in response to low algal concen- 36. MAXIMOVICH, N. V., and A. V. tration. Journal of Experimental Marine Bi- GUERASSIMOVA. 2003. Life history ology and Ecology. 284:105-127. characteristics of the clam Mya arenaria 45. ROPES, J. W., and A. P. STICKNEY. in the White Sea. Helgoland Marine Re- 1965. Reproductive cycle of Mya arenaria search. 57:91-99. in New England. Biological Bulletin. 37. MORSE, B. L., and H. L. HUNT. 2013. 128:315-327. Impact of settlement and early post- 46. ROSEBERRY, L., B. VINCENT, and C. settlement events on the spatial distribu- LEMAIRE. 1991. Growth and reproduction tion of juvenile Mya arenaria on an inter- of Mya arenaria in their intertidal zone of tidal shore. Journal of Experimental Ma- the Saint Lawrence Estuary. Canadian rine Biology and Ecology. 448:57-65. Journal of Zoology. 69:724-732. 38. NORENBURG, J. L., and J. D. FERRA- 47. ROSENBLUM, S. E., and T. M. NIESEN. RIS. 1990. Cytomorphology of the pedal 1985. The spawning cycle of soft-shell aperture glands of Mya arenaria L. clam, Mya arenaria, in San Francisco Bay. (Mollusca, Bivalvia). Canadian Journal of Fishery Bulletin. 83:403-412. Zoology. 68:1137-1144. 48. ST-ONGE, P., J. SEVIGNY, C. 39. PACKARD, E. L. 1918. Molluscan fauna STRASSER, and R. TREMBLAY. 2013. from San Francisco Bay. Zoology. Strong population differentiation of 14:199-452. softshell clams (Mya arenaria) sampled 40. PFITZENMEYER, H. T., and C. N. across seven biogeographic marine ecore- SHUSTER. 1960. A partial bibliography gions: possible selection and isolation by of the softshell clam Mya arenaria Lin- distance. Marine Biology. 160:1065-1081. naeus. Maryland Department of Re- 49. STEWART, J. E., L. J. MARKS, M. W. search and Education, Chesapeake Bio- GILGAN, E. PFEIFFER, and B. M. logical Laboratories, Solomons, MD. ZWICKER. 1998. Microbial utilization of

the neurotoxin domoic acid: blue mus- Linnaeus, 1758) across seagrass com- sels (Mytilus edulis) and soft shell clams plexity: Behavioural mechanisms and a (Mya arenaria) as sources of the micro- new habitat complexity index. Journal of organisms. Canadian Journal of Microbi- Experimental Marine Biology and Ecology. ology. 44:456-464. 446:139-150. 50. STRASSER, M., M. WALENSKY, and K. 57. ZHANG, J., F. XU, and R. LIU. 2012. The REISE. 1999. Juvenile-adult distribution Myidae (Mollusca, Bivalvia) from Chinese of the bivalve Mya arenaria on intertidal waters with description of a new species. flats in the Wadden Sea: why are there Zootaxa:39-60. so few year classes? Helgoland Marine 58. ZWARTS, L. 1991. Seasonal variation in Research. 53:45-55. body weight of the bivalves Macoma 51. TAN, E. B. P., and B. F. BEAL. 2015. In- balthica, Scrobicularia plana, Mya arenaria teractions between the invasive Europe- and Cerastoderma edule in the Dutch an green crab, Carcinus maenas (L.), Wadden Sea. Netherlands Journal of Sea and juveniles of the soft-shell clam, Mya Research. 28:231-245. arenaria L., in eastern Maine, USA. Jour- Updated 2015 nal of Experimental Marine Biology and T.C. Hiebert Ecology. 462:62-73. 52. TAYLOR, D. L., and D. B. EGGLESTON. 2000. Effects of hypoxia on an estuarine predator-prey interaction: foraging behavior and mutual interference in the blue crab Callinectes sapidus and the infaunal clam prey Mya arenaria. Marine Ecology Progress Series. 196:221-237. 53. TAYLOR, J. D., S. T. WILLIAMS, E. A. GLOVER, and P. DYAL. 2007. A molecular phylogeny of heterodont bivalves (Mollusca: Bivalvia: Heterodonta): new analyses of 18S and 28S rRNA genes. Zoologica Scripta. 36:587-606. 54. VINCENT, B., G. DESROSIERS, and Y. GRATTON. 1988. Orientation of the infaunal bivalve Mya arenaria (L.) in rela- tion to local current direction on a tidal flat. Journal of Experimental Marine Biol- ogy and Ecology. 124:205-214. 55. WINCKWORTH, R. 1930. Notes on no- menclature. 5. Some new names for British marine bivalves. Proceedings of the Malacological Society of London. 19:14-15. 56. WONG, M. C. 2013. Green crab (Carcinus maenas Linnaeus, 1758) foraging on soft-shell clams (Mya arenaria